Fast-tunable terahertz wave filter based on Kerr medium

•We present fast-tunable terahertz filter based on nonlinear polymer photonic crystal.•The center wavelength shifts 0.012 mm under the excitation of 25 MW/cm2 pump laser.•Quality factor is from 7600 to 4700 as fabricating tolerance varies from 0% to 20%.

We numerically demonstrate terahertz filter with independently tunable defect mode based on a nonlinear polymer photonic crystal made of polystyrene doped with coumarin. The central frequency of the filtering channel continuously shifts with the increase of pump intensity. The simulated results theoretically provide the principle for fabricating independently tunable terahertz filter by utilizing one-dimensional photonic crystals with defects. The center wavelength shifts about 0.012 mm under the excitation of 25 MW/cm2 pump laser. When manufacturing tolerances varies from 0% to 20%, the quality factor of terahertz wave channel changes from over 7600 to less than 4700. Time response of the terahertz wave filter is in the order of several picoseconds.